FAQ Answer
FAQ Answer
What is a decibel?
The strength of a noise source is usually measured in decibels. Decibels are abbreviated as dB. They are logarithmic units, this is because sound powers and consequently intensities, typical of different sources, cover a very wide range of values.
FAQs
- How do I make a complaint about aircraft noise?
- What is a decibel?
- What does the ‘A’ in the dBA unit mean?
- What is Leq?
- If the number of aircraft noise events is doubled, the noise level only increases by 3 dBA, why?
- What do aircraft noise exposure contours show?
- How are noise contours produced?
- Are there other noise models available, and are they the same as ANCON?
- Why is the 57 dBA contour considered important?
- I live outside the published 57 dBA contour and I am overflown; I can hear aircraft and it annoys me - how is this possible?
- I live outside the published 57 dBA contour, but when I use a sound level meter to measure aircraft noise outside my house, the reading is more than 57 dBA - how is this possible?
- What is Lden?
- How is helicopter noise modelled?
- What are the 'Chapter 2' and 'Chapter 3' aircraft noise classifications?
- What is the new 'Chapter 4' noise standard?
- How do I purchase the latest annual contour reports for Heathrow, Gatwick and Stansted?
- How do I purchase other reports produced by ERCD?
